Electrical Wiring Device with High Current USB Charging Capabilities

ABSTRACT

The present invention is directed to an electrical wiring device that includes an AC power supply control circuit, an isolation interface circuit and a low voltage printed circuit board (PCB) assembly. The low voltage PCB assembly includes a universal serial bus (USB) charging interface circuit configured to convert the modulated power signal into a low voltage direct current (DC) charging signal. The at least one low voltage PCB assembly includes at least one USB socket coupled to the USB charging interface circuit and accessible via the at least one USB aperture formed in the front cover member. The USB charging interface circuit is configured to provide the low voltage DC charging signal to at least one device-under-charge at a maximum predetermined charging current.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is application claims priority under 35 U.S.C. 119 (e) to U.S. Provisional Patent Application Ser. No. 61/635,432, filed on Apr. 19, 2012, the content of which is relied upon and incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to electrical wiring devices, and particularly to devices that include relatively high current USB charging receptacles.

2. Technical Background

Electrical distribution systems deliver power throughout a building from the power source to electrical wiring devices. Electrical wiring devices are connected to the electrical distribution system by way of a plurality of terminals and deliver power from the power source to a load. One or more electrical wiring devices can be mounted to a device box depending on the size of the device box. Once the electrical wiring device is installed inside the device box, a cover plate is disposed over the electrical wiring device to complete the installation. Electrical wiring devices typically include receptacles, switches, ground fault circuit interrupters, GFCIs, arc fault circuit interrupters, AFCIs, transient surge suppressors, TVSSs, occupancy sensors, dimmers, timers, and low voltage devices. These devices were introduced to the market place as the state of the art developed over time. Of course, the state of the art continues to develop.

Indeed, the public has witnessed a technological revolution during the past twenty years or so. During this time, personal computers were introduced to the public and the Internet evolved from an obscure military/research network into the global phenomenon it is today. Computer networks, public switched telephone networks (PSTN), wireless networks as well as individual users send and receive all types of data via the Internet—planet earth is wired—nowadays, almost everyone has at least one processor based device that they use to “get on line.” One should keep in mind, however, that the interconnectivity that we all enjoy was not always this easy.

In the past, interconnecting computers and the various peripheral devices (such as printers, mice, keyboards, and modems) was quite challenging. In early computers, printers were designed to be connected via a parallel printer port, and usually, the computer only supported one printer device. Modems on the other hand, typically used a slow serial port (e.g., 56 kbps) that might have to be shared with discrete devices such as cameras, etc. The universal serial bus (“USB”) emerged as a solution to the problem of connecting various peripheral devices to computers. The USB was designed as a standardized easy-to-use, plug and play connector that can be used to connect up to 127 devices to a computer.

And now there is yet another revolution hard on the heels of the first one. The second revolution, of course, is the wireless revolution and it presents its own set of problems. In the recent past, e.g., people would do their computing from a desk top computer that was hard wired into a wireline network (e.g., CATV, PSTN) and obtained electrical power from a nearby receptacle. Now, people are accessing the Internet wirelessly by way of a variety of wireless devices that includes cell phones, Internet phones, portable lap top or netbook type computers, personal digital assistants, MP3 players, gaming devices and the like. Moreover, cloud computing is now being introduced such that users can access their personal data from “the cloud.” While wireless users can access telecommunication and data services wirelessly, Tesla's dream of providing electrical power in this manner has not been realized. Stated differently, all of these portable devices must obtain power from batteries that, in turn, must be recharged periodically.

In one approach that has been considered, the portable electronic devices referred to above would come with their own power charging devices. Battery chargers are typically heavy and bulky because they need to convert high voltage AC power into the low voltage DC employed by the portable device. The AC/DC conversion thus requires a step down transformer. One of the drawbacks associated with this approach is that it requires the users to lug the separate battery charger along with them everywhere they go or risk battery depletion.

In another approach, a wall mounted electrical receptacle configured to provide both AC power service and low voltage DC power has been considered in light of the drawbacks associated with portable battery chargers. This approach conveniently provided a step down transformer in combination with an AC/DC conversion circuit in an electrical wiring device form factor. One of the drawbacks of this approach relates to the wiring device size and charging current tradeoff. Stated differently, the amount of charging current drawn by the portable device-under-charge is limited by the size of the transformer in the electrical wiring device. The size of the transformer in the electrical wiring device is limited in turn by the size of the electrical wiring device itself. The form factor of an electrical wiring device is constrained by the size of a single gang device box. Heretofore, these size limitations have precluded wall mounted charging devices from providing a charging current of more than 750 mA. While 750 mA may be an appropriate charging current for some of the older portable devices, it is not appropriate for some of the newer devices that draw a larger charging current. Stated differently, the instant inventors have found that some of the newer devices require a much greater charging current and will not, in fact, charge in response to, e.g., a 750 mA current. Other devices will take an inordinate amount of time before they are completely charged.

In yet another approach, a metal raceway system configured to provide both AC power service and higher charging current DC power has been considered in light of the drawbacks associated with relatively low current electrical wiring devices described above. The metal raceway embodiment is also applicable to power strip or power cord applications. Both of these form factors are not limited by the aforementioned size constraints. However, both of these approaches have their own drawbacks. While metal raceways may be appropriate for commercial and industrial applications, they are not aesthetically pleasing in the home environment. And the use of a power strip device takes the problem full circle back to the portable battery charger. No one wants to lug around a separate battery charger or a power strip device with them when they are traveling.

What is needed, therefore, is a wall mountable electrical wiring device that can provide multiple USB receptacles that provide a relatively high charging current for the newer portable devices being introduced to the market. Alternatively, what is needed is a wall mountable electrical wiring device that can provide at least one USB receptacle in combination with a power control device such as an AC outlet receptacle or a switching device.

SUMMARY OF THE INVENTION

The present invention addresses the needs described above by providing a wall mountable electrical wiring device that includes multiple USB receptacles that provide a relatively high charging current. The present invention addresses the needs described above by providing a wall mountable electrical wiring device that includes at least one USB receptacle in combination with a power control device such as an AC outlet receptacle or a switching device.

One aspect of the present invention is directed to an electrical wiring device that includes a housing assembly having a plurality of terminals configured to connect the device to an AC power source. The housing assembly further includes a back body member coupled to a front cover member. The back body member further comprises at least one compartment, the at least one compartment including a separator member configured to divide the at least one compartment into at least one lower compartment and at least one upper compartment. At least one AC printed circuit board (PCB) assembly is disposed under the separator within the at least one lower compartment and including an AC power supply control circuit coupled to the plurality of terminals. The AC power supply control circuit is configured to conduct a power control signal based on at least one feedback parameter. The at least one AC PCB assembly further includes an isolation interface circuit coupled to the AC power supply control circuit. The isolation interface circuit is configured to provide a modulated power signal based on the power control signal and provide a feedback signal corresponding to the at least one feedback parameter to the AC power supply control circuit. At least one low voltage printed circuit board (PCB) assembly is disposed over the separator within the at least one upper compartment spaced apart from the at least one AC PCB assembly. The at least one low voltage PCB assembly includes a universal serial bus (USB) charging interface circuit configured to convert the modulated power signal into a low voltage direct current (DC) charging signal. The at least one low voltage PCB assembly includes at least one USB socket coupled to the USB charging interface circuit and accessible via the at least one USB aperture formed in the front cover member. The USB charging interface circuit is configured to provide the low voltage DC charging signal to at least one device-under-charge at a maximum predetermined charging current.

Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings.

It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the invention and together with the description serve to explain the principles and operation of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an embodiment of an electrical wiring device including two USB receptacle ports and a 120 VAC, 15 A receptacle;

FIG. 2 is a rear view of the device depicted in FIG. 1;

FIG. 3 is an exploded view of the device depicted in FIG. 1;

FIG. 4 is a perspective view of a second embodiment of an electrical wiring device including two USB receptacle ports and an electrical switch;

FIG. 5 is a rear view of the device depicted in FIG. 4;

FIG. 6 is an exploded view of the device depicted in FIG. 4;

FIG. 7 is a schematic diagram of a USB receptacle circuit in accordance with the present invention;

FIG. 8 is a perspective view of the AC printed circuit board (PCB) assembly depicted in FIGS. 3 and 6, and shown schematically in FIG. 7;

FIG. 9 is a perspective view of the low voltage printed circuit board (PCB) assembly depicted in FIGS. 3 and 6, and shown schematically in FIG. 7;

FIG. 10 is a perspective view of an embodiment of an electrical wiring device including two spaced apart USB receptacle ports;

FIGS. 11A-H are flow diagrams illustrating an assembly sequence for the electrical wiring device depicted in FIG. 10;

FIGS. 12A-B is a perspective view of an embodiment of an electrical wiring device including two USB receptacle ports and two single pole switches;

FIG. 13 is a perspective view of an embodiment of an electrical wiring device including two USB receptacle ports and a 120 VAC, 20 A receptacle;

FIG. 14A-14B are perspective views of an embodiment of an electrical wiring device in accordance with alternate embodiments of the invention;

FIGS. 15A-C are various views of a single module electrical device configured for insertion in a modular framing assembly in accordance with yet another embodiment of the present invention;

FIG. 16 is an exploded view of the electrical device depicted in FIG. 15;

FIG. 17 is a perspective view of the AC printed circuit board (PCB) assembly depicted in FIGS. 15 and 16;

FIG. 18 is a perspective view of the low voltage printed circuit board (PCB) assembly depicted in FIGS. 15 and 16;

FIG. 19 is a perspective view of an alternate embodiment of an electrical wiring device including two USB receptacle ports and a 120 VAC, 15 A receptacle; and

FIG. 20 is a perspective view of another alternate embodiment of an electrical wiring device including two USB receptacle ports and a 120 VAC, 15 A receptacle.

DETAILED DESCRIPTION

Reference will now be made in detail to the present exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. An exemplary embodiment of the electrical wiring device of the present invention is shown in FIG. 1, and is designated generally throughout by reference numeral 10.

As embodied herein, and depicted in FIG. 1, a perspective view of an embodiment of an electrical wiring device 10 is disclosed. This embodiment of the present invention includes a front cover 12 that has dual USB receptacle ports 12-1 and a 120 VAC, 15 A receptacle 12-2. The front cover 12 mates with a back body member 14. Back body member 14 includes vent openings 14-1 that allows thermal energy generated by the internal circuitry to dissipate. A mounting strap 16 is coupled to the back body member 14 and provides the means for the user to connect the device 10 to a device box installed in a wall opening (not shown). FIG. 2 is a rear view of the device depicted in FIG. 1. In this view, the vent openings 14-1 are shown to be disposed in both the side and rear portions of the back body member 14. The device 10 includes a hot terminal 18 and a neutral terminal 19 that allow the device 10 to be connected to AC power. Once the device is installed, a cover plate (not shown) surrounds front cover 12 to complete the enclosure. By completing the enclosure, the inventors mean that no electrical charged components or electrical distribution wires connected to terminals 18, 19 are accessible to the user after the plate is in place.

Referring to FIG. 3, an exploded view of the device depicted in FIG. 1 is disclosed. As noted above, the device 10 includes a housing assembly that has back body member 14 coupled to the front cover member 12. The plurality of terminals (18, 19) is configured to connect the device 10 to a source of AC power. The back body member 14 includes compartments 14-2, 14-3. The compartment 14-2 is configured to accommodate a separator member 15 that is further configured to divide compartment 14-2 into a lower compartment and an upper compartment. Thus, during assembly, the AC printed circuit board (PCB) assembly 140 is inserted into the first compartment 14-2, the separator member 15 is disposed over top, and then the low voltage PCB assembly 120 is placed on top of the separator 15.

The second compartment 14-3 is configured to accommodate a 120 VAC, 15 A receptacle outlet assembly (16-1, 18-1, 19-1), and thus includes a series of rib structures 14-30 that are used to insulate the various electrical conductive portions of the receptacle and prevent them from shorting out. In particular, note that the hot terminal structure includes an integrally formed hot receptacle contact 18-1 that is configured to accept the hot plug blade of a plug blade set. The neutral terminal structure 19 includes an integrally formed neutral receptacle contact 19-1 that is configured to accept the neutral plug blade of a plug blade set. Tamper-resistant shutters 20 are disposed between contacts 18-1, 19-1 and receptacle openings 12-2 in the front cover. Shutters 20 are in the closed position and prevent a foreign object inserted into openings 12-2 from being able to touch contacts 18-1, 19-1. The shutters open when a suitable plug is inserted allowing the blades of the plug to electrically connect to contacts 18-1, 19-1. Reference is made to U.S. patent application Ser. Nos. 13/487,960 and 13/487,547, which are incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of a shutter assembly. Finally, the ground mounting strap 16 includes a ground receptacle contact 16-1 that is configured to accept the ground prong of a plug blade set. Ground terminal 16-2 allows the device to be connected to a grounding conductor in the electrical distribution system.

Referring to the AC printed circuit board (PCB) assembly 140 disposed under the separator member 15, it includes an AC power supply control circuit coupled to the plurality of terminals (18, 19). As described below in greater detail, the AC power supply control circuit is configured to conduct a power control signal based on various feedback parameters. The AC PCB assembly 140 further includes an isolation interface circuit that is coupled to the AC power supply control circuit. The isolation interface circuit is configured to provide a modulated power signal based on the power control signal and provide a feedback signal corresponding to at least one of the feedback parameters to the AC power supply control circuit. The AC PCB 142 is substantially normal to separator member 15. Since the height of the isolation transformer and possibly other components is greater than the width of the AC PCB 142, this minimizes the overall height dimension of the housing assembly. Again, the components and operation of the AC assembly 140 is described in greater detail below.

Referring to the low voltage printed circuit board (PCB) assembly 120 disposed over the separator member 15, it includes a universal serial bus (USB) charging interface circuit that is configured to convert the modulated power signal (of the AC assembly 140) into a low voltage direct current (DC) charging signal. The low voltage PCB assembly 120 includes two single port USB sockets 120-1, 120-2 coupled to the USB charging interface circuit. Low voltage PCB 122 is parallel to separator member 15. Thus the sockets 120-1, 120-2 are each accessible via the USB apertures 12-1 formed in the front cover member 12. In an embodiment of the invention, the center lines of the two single port USB sockets are spaced apart by about 0.5 inches whereas known unitized dual port USB sockets are spaced apart by about 0.3 inches. Series “A” USB plugs are about 0.3 inches wide. By using single port sockets and going to a greater separation distance it is easier to insert and remove a plug while the other one is in use. The USB charging interface circuit is configured to provide the low voltage DC charging signal to two devices-under-charge at a maximum predetermined charging current. In one embodiment, the maximum charging current provided by assembly 120 is approximately 2.1 Amperes.

As embodied herein and depicted in FIG. 4, a perspective view of a second embodiment of an electrical wiring device 10 is disclosed. This embodiment includes a front cover 12 that includes the dual USB receptacle ports 12-1, a three-way electrical switch 12-3 and modular element 12-4. The modular element 12-4 may be implemented as a light element or as a blank element. The front cover 12 is coupled to the back body member 14 as before. FIG. 5 is a rear view of the device depicted in FIG. 4. As shown, the device 10 has a plurality of terminals that includes hot line terminal 18, neutral line terminal 19, and traveler terminals 17-1, 17-2, one or the other connecting to hot line terminal 18 depending on how the switch is thrown.

Referring to FIG. 6, an exploded view of the device depicted in FIG. 4 is disclosed. Again, the device 10 includes a housing assembly that has back body member 14 coupled to the front cover member 12. The front cover 12 includes USB receptacle ports 12-1 disposed in the distal half portion of front cover 12 and a switch actuator compartment 12-30 disposed in the proximal half portion of front cover 12. The switch compartment 12-30 further includes module compartment 12-40. The module compartment 12-40 is configured to accommodate modular element 12-4. Reference is made to U.S. Pat. No. 7,360,912, filed on Oct. 24, 2005, which is incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of the lighting module 12-4.

The back body member 14 includes compartments 14-2, 14-3. The compartment 14-2 is configured to accommodate a separator member 15 that is further configured to divide compartment 14-2 into a lower compartment and an upper compartment. Thus, during assembly, the AC printed circuit board (PCB) assembly 140 is inserted into the first compartment 14-2, the separator member 15 is disposed over top, and then the low voltage PCB assembly 120 is placed on top of the separator 15. The second compartment 14-3 is configured to accommodate the switch assembly 110. Switch assembly 110 includes a pivoting member 110-1 that is coupled to paddle switch actuator 12-3 via spring element 110-2. When the user actuates the paddle switch 12-2, the pivoting member 110-1 moves between fixed contact 17-10 and 17-20. If the switch is configured as a three-way switch, terminals 17-1, 17-2 are connected to traveler wires. If the switch is configured as an ON/OFF switch, one of the traveler terminals is either omitted or left unconnected and represents an OFF position. The hot and neutral terminals (18, 19) are configured to connect the device 10 to a source of AC power. Reference is made to U.S. Pat. No. 7,360,912, filed on Oct. 24, 2005, or U.S. Pat. No. 7,497,582, filed on Jan. 30, 2006, which are incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of the switch assembly 110.

The low voltage PCB assembly 120 and the AC PCB assembly 140 were discussed above in the discussion of the first embodiment of FIGS. 1-3.

Referring to FIG. 7, a schematic diagram of a USB receptacle circuit 100 in accordance with the present invention is disclosed. At a very high level, the circuit 100 includes the low voltage PCB assembly 120 and the AC PCB assembly 140 previously referred to.

The AC PCB assembly may be thought of as including three portions: a power supply portion 140-1, an isolation circuit 140-2, and a modulation portion 140-3. The power supply portion 140-1 is coupled to an AC power source via hot and neutral terminals 18, 19, respectively. The hot terminal 18 is connected to a fuse F1 that is configured to protect the circuit 100 and the device under charge from excessive current. The inductor coil L1 is employed as a front end common-mode noise filter (A common-mode signal typically propagates on the line and neutral signal paths, in-phase and with equal amplitudes). Next, the hot and neutral conductors are connected to the full wave bridge rectifier BR1 which yields approximately 170 V-Peak at the output, which is across resistor R11. The rectified output is provided to the modulation circuit 140-3 U1 by way of resistors R4 and R5. Resistors R4 and R5, of course, are used to scale the current from BR1 to an appropriate level for use by the modulation circuit U1. The rectified output voltage is also provided to the isolation circuit 140-2. In particular, the rectified output is coupled to the primary side 140-20 of the isolation transformer 140-2 by way of a conditioning circuit that includes resistor R11, capacitors C1, and C2, and inductor L2. The other side of the primary 140-20 is connected to the transistor Q1, which is controlled by the modulation integrated circuit (IC) U1.

The modulation portion 140-3 of the AC PCB assembly 140 includes a modulation IC U1 coupled to transistor Q1. Modulation IC U1 controls the base of transistor Q1 base with a pulse width modulated signal. When Q1 is turned ON and OFF, the rectified voltage across capacitor C2 is pulled through the primary side 140-20 of the isolation transformer 140-2 such that a pulse width modulated (PWM) signal is propagated through the primary 140-20. Stated differently, the cyclic behavior of the PWM signal creates an AC type input on the primary 140-20 of the transformer T1, which also appears on the secondary 140-22 as well as in the auxiliary windings 140-24 of the transformer 140-2. The auxiliary portion 140-24 senses the amount of current drawn by the low voltage PCB assembly 120 and provides the sensor feedback information to the modulation IC U1 via resistors R1, R2 and R12.

Referring back to the power supply circuit 140-1, note that the combination of diode D1, resistors R7 and R6, and capacitor C4 form a snubber circuit (i.e., a LVTVSS). Diode D1 also serves as a fly-back path for the primary 140-20.

Again, the transformer 140-2 conducts a PWM signal which is inductively coupled to the transformer secondary 140-22. The PWM signal is directed into the low voltage PCB assembly 120. The secondary 140-22 of the transformer 140-2 is rectified by diode D5, and further conditioned by the parallel combination of capacitors C5, C12, C13, C14, and C15, and resistors R17 and R18. The final +5 VDC output is provided to the positive (+) power terminal of each USB connector, 120-1 and 120-2, respectively. The negative (−) power terminal of the connectors (120-1, 120-2) are connected to ground. The USB connectors 120-1 and 120-2 are, of course, connected in parallel. The data terminals of each USB connector (120-1, 120-2) maybe shorted together. The schematic shows the data terminals (D+, D−) of USB connector 120-1 being connected to resistor R19, whereas the data terminals (D+, D−) of USB connector 120-2 are connected to resistor R20. Note that resistors R19 and R20 are depicted herein and, in an alternate embodiment, may have a resistance of up to 200 ohms (per USB 1.2 standard). Finally, the neutral terminal of the secondary 140-22 is connected to a capacitor CY1, the other end of which is connected to the auxiliary windings 140-24 of the transformer 140-2. Stated differently, the capacitor CY1 provides an AC path from the secondary 140-22 to the primary 140-20 side ground to limit noise present at the negative terminals (−) of the USB connectors. Of course, the jumper J1 can be opened to remove capacitor CY1 as needed.

It will be apparent to those of ordinary skill in the pertinent art that modifications and variations can be made to modulator IC U1 of the present invention depending on the degree of sophistication required by the application. For example, secondary 140-20 voltage feedback may be used for output voltage regulation. In FIG. 7, pin 2 (Vsense) of the modulator IC U1 provides this functionality by acting as a sensor signal input from the auxiliary winding. In particular, the output of the auxiliary transformer 140-24 is conditioned by resistors R2, R1, R15, and R12, diode D3, and capacitor C11 before being directed into the sensor input at pin 2.

As noted previously, the rectified line voltage is provided to the modulator IC U1 by the VIN pin (3). VIN is used by the IC U1 to monitor input undervoltage and overvoltage conditions. The VIN pin also provides the supply current to the IC during start-up. Again, current derived from the input line voltage is scaled down using a resistor network R4 and R5. The resistor network is further coupled to capacitor C8, which is selected to filter noise generated as a result of a MOSFET internal to the modulator IC U1.

Another capability that may be included in modulator IC U1 is temperature and power supply overvoltage monitoring via the “shutdown” (SD) pin 4. The modulator IC U1 alternates between monitoring temperature and overvoltage conditions. Power supply over-voltage conditions may be brought on by high line voltage. Over-temperature conditions may be brought on by trying to charge two batteries at a time and the net charging current exceeding a maximum predetermined current. Ostensibly transformer 140-2 overheats. When monitoring for a high temperature condition, the IC U1 monitors temperature sensor output NTC. The NTC senses the temperature of the power supply circuit since it is disposed either within or adjacent to the first compartment 14-2. If either an overvoltage condition or an over-temperature condition is detected, a latch inside the IC U1 is activated to decouple the VCC pin from the power supply. Finally, the gate drive of the external MOSFET Q1 is provided by the output pin 7.

In one embodiment of the present invention, the modulator IC U1 may operate in critical discontinuous conduction mode (CDCM) or pulse width modulation (PWM) mode at high output power levels and switch to Pulse Frequency Modulation (PFM) mode at light loads to minimize power dissipation.

In one embodiment of the present invention, a switch in series with fuse F1 is employed that is turned OFF when the USB charger is not in use. This feature may be used in conjunction with any embodiment of the present invention. See, e.g., FIGS. 19 and 20.

Referring to FIG. 8, a perspective view of the AC printed circuit board (PCB) assembly depicted in FIGS. 3 and 6 is disclosed. The AC PCB assembly 140 components and interconnections are shown schematically in FIG. 7 which was described above. Various components of the AC PCB assembly 140, such as transformer 140-2, capacitors C1 and C2, and inductor coil L1 are shown as being mounted on the printed circuit board 142. The secondary conductors 144A (hot) and 144B (neutral) are shown as being connected to the transformer (T1) 140-2. Hot and neutral conductors (18′, 19′) are connected to terminals 18, 19 shown in FIGS. 5-7 In another embodiment of the invention, conductors 18′ and 19′ are connected to neutral terminal 19 and to either terminal 17-10 or 17-20, respectively. Switch actuator 12-3 still controls a remote load but now in addition turns line voltage to the charger on and off.

Referring to FIG. 9, a perspective view of the low voltage printed circuit board (PCB) assembly 120 depicted in FIGS. 3 and 6 is disclosed. The low voltage PCB assembly components and interconnections are shown schematically in FIG. 7 described above. Various components of the low voltage PCB assembly 120, such as capacitors C5, C14, C13, and CY1, as well as the USB connectors (120-1, 120-2), are shown as being mounted on the printed circuit board 122.

As embodied herein and depicted in FIG. 10, a perspective view of another embodiment of an electrical wiring device 10 is disclosed. This embodiment includes two spaced apart USB receptacle ports 12-10 disposed in the front cover 12. In this embodiment, each USB port 12-10 can provide up to 2.1 A of current. One of the USB receptacle ports 12-10 occupies the space previously used for a receptacle or switch according to other embodiments of the invention.

Referring to FIGS. 11A-H, flow diagrams illustrating an assembly sequence for the electrical wiring device depicted in FIG. 10 are disclosed. In FIG. 11A, the back body member 14 is coupled to the mounting strap 16. In FIGS. 11B and 11C, two AC PCB assemblies 140 are installed inside the back body 14. In FIGS. 11D and 11E, the hot line contact 18 and the neutral line contact 19 are installed in the back body member and coupled to the two AC PCB assemblies 140. FIG. 11F shows the separator member 15 being connected to the back body 14 to enclose the two AC PCB assemblies 140 there within. In FIGS. 11G and 11H, two low voltage PCB assemblies 120 are coupled to the top side of the separator member 15. The PCB assemblies may employ the same printed circuit board 122 that has been described with one of the single port USB receptacles omitted. The secondary connections (144A, 144B) from the transformer 140-2 are connected to the low voltage PCB assemblies 120. Once these steps are finished, the front cover 12 (not shown in this view) is coupled to the back cover 14 to complete the device 10 assembly.

As embodied herein and depicted in FIG. 12A, a perspective view of an embodiment of an electrical wiring device including dual USB receptacle ports 12-1 and two single pole switches 12-5 is disclosed. This embodiment also may include the modular element 12-4 described above. Turning to FIG. 12B, a perspective view of the switch actuator is depicted. The switches 115 disclosed in this embodiment are similar to the switch disclosed in FIGS. 4-6. Each switch includes a single stationary contact 115-1 such that each switch is configured as an ON/OFF (single pole-single throw) switch. Each stationary contact 115-1 is connected to a hot wire lead 200 which are, in turn, is connected to a hot terminal 18. When the pivot member 115-3 is rotated such that its contact 115-2 is engaged with stationary contact 115-1, the switch is turned ON. Otherwise and the switch 115 is OFF. Wires 200 may themselves constitute wiring terminals, being attached to conductors from the electrical distribution system using twist on connectors or similar fasteners. In an alternate embodiment (not shown), a second stationary contact connected to a traveler contact may be provided. In this alternate embodiment, one of both of the switches is configured as a three-way switch. Reference is made to U.S. Pat. No. 7,360,912, filed on Oct. 24, 2005, which is incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of the lighting module 12-4. Reference is made to U.S. Pat. No. 7,360,912, filed on Oct. 24, 2005, or U.S. Pat. No. 7,497,582, filed on Jan. 30, 2006, which are incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of the switch assembly 115.

As embodied herein and depicted in FIG. 13, a perspective view of an embodiment of an electrical wiring device including dual USB receptacle ports and a 120 VAC, 20 A receptacle is disclosed. This embodiment is similar to the one depicted in FIGS. 1-3, the difference being that receptacle 12-6 is configured to accept a 20 A plug blade set.

As embodied herein and depicted in FIG. 14A, a perspective view of an embodiment of an electrical wiring device including four USB receptacle ports is disclosed. This embodiment is similar to the one depicted in FIG. 11, the exception being that the low voltage PCB assembly includes the dual USB connectors 120-1, 120-2 (as shown, e.g., in FIG. 3). Thus, the two USB ports 12-1 shown at the distal end of the device 10 in FIG. 14 provide up to 2.1 A of charging current. Similarly, the two proximal ports 12-1′ also provide up to 2.1 A of charging current. The assembly sequence is similar to the one shown in FIG. 11. As shown in FIG. 14B, the proximal set of USB ports 12-1′ may be eliminated such that the proximal end of the front cover assembly 12 is blank.

As embodied herein and depicted in FIGS. 15A-C, various views of a single module electrical device configured for insertion in a modular framing assembly in accordance with yet another embodiment of the present invention is disclosed. Module 1000 depicted in FIGS. 15-18 is configured to be deployed within a modular electrical wiring device system 10 that includes a frame assembly disposed in the device wall box. The module is inserted until the snap elements 14-2 engage corresponding elements in the frame. Reference is made to U.S. Provisional Patent Application Ser. No. 61/635,432, filed on Apr. 19, 2012, which is incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of the Modular Electrical Wiring Device System.

The dimensions of the module 1000 are provided in FIGS. 15A-C. Due to its dimensions, module 1000 is referred to as a “one module device.” In the Modular Electrical Wiring Device System, a single gang device box accommodates three modules. Thus, three USB devices 10 may be stacked on their side (i.e., on the 45 mm side) within a single gang box. Alternatively, the single module USB module 1000 depicted herein may be deployed in a single gang device box with, for example, a two module device, such as a switch module or a receptacle outlet module. Thus, the Modular Electrical Wiring System may be configured to include various kinds of devices such as the electrical wiring devices shown in FIGS. 1-14.

Referring to FIG. 16, an exploded view of the electrical device depicted in FIGS. 15A-C is disclosed. Since module 1000 is disposed in a form factor approximately one-third of the size of the devices depicted in FIGS. 1-14, the back body 14 includes a single compartment that accommodates AC PCB assembly 140, separator member 15 and the low voltage PCB assembly 120. The front cover includes one USB port 12-1 and snaps into the back body by way of snaps 14-3. The single USB port 120-10 in PCB assembly 120 provides a maximum current of about 2.1 A. The back body 14 snaps into the frame system disclosed in U.S. Provisional Patent Application Ser. No. 61/635,432 via snap elements 14-2 to thereby complete the enclosure. A strictly aesthetic cover plate is then disposed around the front cover to complete the installation. Completing the enclosure means that neither the electrical distribution wires or are accessible to the user even if the aesthetic plate is removed.

In reference to FIG. 17, a perspective view of the AC printed circuit board (PCB) assembly 140 depicted in FIG. 16 is disclosed. Assembly 140 is identical to the one depicted in FIG. 8. The underside of the PCB 142 is shown in this view however. As shown, the MOSFET Q1 and the modulator IC U1 are shown as being mounted to the PCB 142. Hot and neutral terminal wires are connected to the PCB 140 to provide AC power to the device from the electrical distribution system once the system is installed and energized.

FIG. 18 is a perspective view of the low voltage printed circuit board (PCB) assembly 120 depicted in FIG. 16. The assembly 120 is very similar to the one depicted in FIG. 9, the difference being that the assembly 120 in the modular embodiment of FIGS. 15-18 only includes a single USB connector 120-10. Like the embodiment of FIGS. 10-11, the USB receptacle can provide up to 2.1 A to a DUC. In another embodiment of the invention module 1000 includes two single receptacle USB ports 120-1 and 120-2 that together provide about a maximum current of 2.1 A.

In reference to FIG. 19, a perspective view of an alternate embodiment of the electrical wiring device depicted in FIGS. 1-3 is disclosed. This embodiment includes a slide switch 150 actuator that is accessible to a user. As described above, the switch actuator is a simple SPST switch disposed in series with the fuse F1 shown in FIG. 7. FIG. 20 is a perspective view of yet another alternate embodiment of the electrical wiring device depicted in FIGS. 1-3. In this embodiment, the switch 150′ is depicted as a push button switch. The switch embodiments of FIGS. 19-20 can obviously be applied to each of the embodiments described herein. Moreover, other types of SPST switch actuators may be employed. Thus, the present invention should not be construed as being limited to the embodiments depicted in FIGS. 19-20.

All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening.

The recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein.

All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments of the invention and does not impose a limitation on the scope of the invention unless otherwise claimed.

No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. There is no intention to limit the invention to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 

What is claimed is:
 1. An electrical wiring device comprising: a housing assembly including a plurality of terminals configured to connect the device to an AC power source, the housing assembly further including a back body member coupled to a front cover member, the back body member further comprising at least one compartment, the at least one compartment including a separator member configured to divide the at least one compartment into at least one lower compartment and at least one upper compartment; at least one AC printed circuit board (PCB) assembly disposed under the separator within the at least one lower compartment and including an AC power supply control circuit coupled to the plurality of terminals, the AC power supply control circuit being configured to conduct a power control signal based on at least one feedback parameter, the at least one AC PCB assembly further including an isolation interface circuit coupled to the AC power supply control circuit, the isolation interface circuit being configured to provide a modulated power signal based on the power control signal and provide a feedback signal corresponding to the at least one feedback parameter to the AC power supply control circuit; and at least one low voltage printed circuit board (PCB) assembly disposed over the separator within the at least one upper compartment spaced apart from the at least one AC PCB assembly, the at least one low voltage PCB assembly including a universal serial bus (USB) charging interface circuit configured to convert the modulated power signal into a low voltage direct current (DC) charging signal, the at least one low voltage PCB assembly including at least one USB socket coupled to the USB charging interface circuit and accessible via the at least one USB aperture formed in the front cover member, the USB charging interface circuit being configured to provide the low voltage DC charging signal to at least one device-under-charge at a maximum predetermined charging current.
 2. The device of claim 1, further comprising a mounting strap configured to affix the device to a device box, the device being configured to accommodate a cover plate to complete the enclosure.
 3. The device of claim 1, further comprising a frame assembly configured to affix the device to a device box, the housing assembly being configured as modular housing insertable into the frame assembly to thereby complete the enclosure.
 4. The device of claim 3, wherein the device box is a single gang device box and the frame assembly accommodates up to three modules selected from a group of modules including a USB module, an electrical switch module, or an outlet receptacle module.
 5. The device of claim 3, further comprising an aesthetic cover plate that is configured to be connected to the frame assembly, the aesthetic cover plate not completing the enclosure.
 6. The device of claim 1, wherein the plurality of terminals include a plurality of line terminals, a plurality of feed-through load terminals or a plurality of receptacle load terminals.
 7. The device of claim 1, wherein the isolation interface circuit provides DC isolation between the at least one AC PCB assembly and the at least one low voltage PCB assembly.
 8. The device of claim 1, wherein the modulated power signal includes a pulse width modulated signal.
 9. The device of claim 1, wherein the maximum predetermined charging current is greater than two amperes (2 A).
 10. The device of claim 1, wherein the at least one compartment includes a first compartment and a second compartment side-by-side adjacent thereto.
 11. The device of claim 10, further comprising an electrical switch assembly including at least one user actuatable switch disposed in the second compartment, the electrical switch assembly being coupled to the AC power source via the plurality of terminals.
 12. The device of claim 10, wherein the USB charging interface circuit includes a first single port USB socket spaced apart from a second single port USB socket, the first single port USB socket and the second single port USB socket being accessible via a first USB aperture and a second USB aperture, respectively, formed in a first portion of the front cover member corresponding to the first compartment.
 13. The device of claim 12, further comprising an electrical receptacle disposed in the second compartment, the electrical outlet receptacle being coupled to the AC power source via the plurality of terminals.
 14. The device of claim 12, further comprising an electrical switch assembly that includes at least one user actuatable switch disposed in the second compartment, the electrical switch assembly being coupled to the AC power source via the plurality of terminals.
 15. The device of claim 14, wherein the electrical switch assembly includes at least one switch actuator disposed adjacent a modular element that substantially spans a width of the second compartment.
 16. The device of claim 15, wherein the modular element is a lighting element.
 17. The device of claim 16, wherein the lighting element is configured to be illuminated when the at least one switch actuator is turned OFF.
 18. The device of claim 14, wherein the electrical switch assembly is a mechanical ON/OFF switch.
 19. The device of claim 18, wherein the electrical switch assembly includes a paddle switch actuator.
 20. The device of claim 12, wherein the first single port USB socket and the second single port USB socket combined are configured to provide the maximum predetermined charging current.
 21. The device of claim 20, wherein the maximum predetermined charging current is greater than two amperes (2 A).
 22. The device of claim 10, wherein the at least one AC PCB assembly includes a first AC PCB assembly disposed in the first compartment and a second AC PCB assembly disposed in the second compartment, and the at least one low voltage PCB assembly includes a first low voltage PCB assembly disposed in the first compartment and a second low voltage PCB assembly disposed in the second compartment.
 23. The device of claim 22, wherein a first USB charging interface circuit of the first low voltage PCB assembly includes a first single port USB socket spaced apart from a second single port USB socket, the first single port USB socket and the second single port USB socket being accessible via a first USB aperture and a second USB aperture, respectively, formed in a first portion of the front cover member corresponding to the first compartment, and wherein a second USB charging interface circuit of the second low voltage PCB assembly includes a third single port USB socket spaced apart from a fourth single port USB socket, the third single port USB socket and the fourth single port USB socket being accessible via a third USB aperture and a fourth USB aperture, respectively, formed in a second portion of the front cover member corresponding to the second compartment.
 24. The device of claim 23, wherein the first single port USB socket and the second single port USB socket combined are configured to provide the maximum predetermined charging current, and wherein the third single port USB socket and the fourth single port USB socket combined are configured to provide the maximum predetermined charging current.
 25. The device of claim 24, wherein the maximum predetermined charging current is greater than two amperes (2 A).
 26. The device of claim 22, wherein a first USB charging interface circuit of the first low voltage PCB assembly includes a first single port USB socket accessible via a first USB aperture formed in a first portion of the front cover member corresponding to the first compartment, and wherein a second USB charging interface circuit of the second low voltage PCB assembly includes a second single port USB socket accessible via a second USB aperture formed in a second portion of the front cover member corresponding to the second compartment.
 27. The device of claim 26, wherein the first single port USB socket is configured to provide the maximum predetermined charging current, and wherein the second single port USB socket is configured to provide the maximum predetermined charging current.
 28. The device of claim 1, wherein the at least one feedback parameter includes an amount of DC current being drawn by at least one device-under-charge.
 29. The device of claim 1, wherein the at least one feedback parameter includes an ambient temperature proximate the at least one AC PCB assembly.
 30. The device of claim 1, wherein the isolation interface circuit is configured to provide the AC power supply control circuit with a feedback signal corresponding to the amount of DC current being drawn by at least one device-under-charge.
 31. The device of claim 1, wherein the isolation interface circuit includes a transformer circuit.
 32. The device of claim 31, wherein the modulated power signal is provided to the at least one low voltage PCB assembly via the transformer circuit.
 33. The device of claim 1, wherein the USB charging interface circuit includes a rectifier circuit to convert the modulated power signal into a low voltage direct current (DC) charging signal.
 34. The device of claim 33, wherein the low voltage direct current (DC) charging signal is approximately +5 VDC.
 35. The device of claim 1, wherein the at least one AC PCB assembly includes a first printed circuit board and the at least one low voltage PCB assembly includes a second printed circuit board that is substantially normal to the first printed circuit board.
 36. The device of claim 1, wherein the back body member includes vent holes adjacent to the lower compartment. 